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Place-based adaptation solutions for South African settlements
Adaptation Futures Conference
21 June 2018
Willemien van Niekerk, CSIR Built EnvironmentCo-authored by Alize le Roux, Amy Pieterse & the Green Book team
context
The Green Book
Urban
povertyClimate
changeAir
pollution
Inadequate
infrastructure
Lack of capacity
Based on UN-Habitat (2018)
Unaffordable
housingExclusion &
inequality
Congestion
Insufficient public
transport
Lack of participatory
process
Surging
youthAgeing
populationInsanitary water
Informal
settlement
Urban
sprawl
Unplanned
city extension
Urbanisation challenges in South Africa
The Green Book
Natural disaster risk in South Africa
Summary of the impacts of recorded climate-related events in South Africa
between 1977-2017 (source: EMDAT CRED, 2018)
The Green Book
Climate eventNo. of
events
No. of
deaths
No. of
homeless
No. of
injured
Total
population
affected
Total damage
in US$
Drought 8 20.17 million 1.25 billion
Extreme
temperature3 63 20
Flood 33 1 198 30 885 370 580 356 1.96 billion
Landslide 1 34
Storm 27 260 16 200 1 357 651 451 1.37 billion
Wildfire 10 137 11 350 530 12 880 8.6 million
Total 82 1 692 58 435 2 277 21.41 million 5.43 billion
future risk trajectory- the western cape
The Green Book
The Green Book
Projected population change (2050 relative to 2011)
Medium growth scenario
Western Cape population growth projection
The Green Book
Projected population change (2050 relative to 2011)
Medium growth scenario
1. High % of
population have
no secondary
education
2. High % of HH
live under
Minimum Living
Level
The Green Book
Western Cape vulnerability indicators
The Green Book
Western Cape climate change projectionsIncreased in no. very hot days
2050 relative to 2011
Low mitigation scenario
The Green Book
Western Cape hazard exposure: WildfireIncrease in no. of fire danger days
2050 relative to 2011
Low mitigation scenario
The Green Book
Western Cape hazard exposure: DroughtDrought Index (SPI)
2040-2060 relative to 1995-2024
Low mitigation scenario
2011
2050
Coastal Flooding Index
& percentage people
uninsured
Estimated 10 751 people exposed
to coastal flooding.
Medium growth scenario &
IPCC sea-level rise estimate
The Green Book
Western Cape hazard exposure: Coastal floodingCoastal Flooding Index
& percentage people
exposed
Hotter & Drier
#1 Deciduous (Wine
grapes)Reduction in available winter chill
and increased summer heat stress.
Warming can negatively affect
quality of the grapes for
winemaking.
Increased evapotranspiration and
irrigation requirements.
Reduced suitability for
viticulture.
Hotter & Drier
#2 Milk & Cream
Potential increase in heat stress
which could negatively affect
conception rates, milk yield and
milk quality.
2.12 % Loss in Agriculture
GDP
Hotter & drier
#3 Chickens
Increased production costs (and
increased investment will be
required in ventilation and
cooling) to maintain optimal
seasonal temperatures and reduce
the risk of heat stress.
Heat stress on birds will reduce
body weight gain, reproduction
efficiency and egg quality.
The Green Book
Western Cape climate change impact: Agriculture2050 population distribution
(medium growth scenario) &
impact of CC on agriculture
(low mitigation scenario)
good practice
The Green Book
Inland
Flooding
Coastal
Flooding
Increased
Wind
Speed
Drought
Heat
Stress
Wildfire
Landscape &
Urban Design
Engineering
Services[Water, Energy,
Stormwater, Sanitation,
Solid Waste, Mobility& Transport]
Environmental
Planning
Ad
ap
tatio
n A
ctio
ns
Win-winNo
regretsLow
regrets
Design
Expand
Restore
The Green Book
Land Use
Management
Spatial
PlanningIdentify Protect
Place-based adaptation actions
Maintain
Protect
Retrofit/design
Maintain
Inland
Flooding
Coastal
Flooding
Increased
Wind
Speed
Drought
Heat
Stress
Wildfire
Landscape &
Urban Design
Engineering
Services[Water, Energy,
Stormwater, Sanitation,
Solid Waste, Mobility& Transport]
Environmental
Planning
Ad
ap
tatio
n A
ctio
ns
Win-win
Design
Expand
The Green Book
Land Use
Management
Spatial
Planning
Protect
Retrofit/design
Maintain
Identify Protect
Maintain
RestoreAdaptation actions for the Western Cape
De
term
ine
co
ast
al
ma
na
ge
me
nt
lin
es
Spatial
Planning
Description
Identify coastal management lines for coastal settlements at risk of rising sea levels and coastal
flooding. Coastal management lines are used as planning tools for coastal retreat and define
the amount of open space between the shoreline and infrastructure (buildings, houses etc.).
Management lines allows room for the average high water mark to naturally move inland by
sea level rise throughout the economic lifetime of the property. Demarcation of coastal
management lines should be informed by wave action, erosion, dune migration and the
location of existing developments. The historic erosion rates or extreme weather levels need to
be taken into account and should be specific to area implemented. Once coastal
management lines have been determined, they need to be reviewed every five years. The
coastal management should be included in the SDF.
Goals
To provide information in support of protecting coastal public and private property from risk,
and protecting environmentally sensitive coastal areas from development.
Benefits
Once coastal management lines are identified and subsequently reviewed, every five years, it
allows local government to better manage their coastal areas, protect infrastructure, and
ensure public safety. They can also be used to complement other coastal adaptation options
such as dune rehabilitation and wetland restoration
Costs
Consultation services would be required to assess erosion rates and water levels, and to model
coastline evolution. If an area is classified as a no-build zone, this could be problematic if the
land has been privately purchased or there are existing structures in the area.
Example
Western Cape Government Environmental Affairs and Development Planning. 2013. Coastal
Set-back Lines for the West Coast District. Coastal Processes and Risk Modelling:
https://www.westerncape.gov.za/eadp/sites/eadp.westerncape.gov.za/files/news/files/2013-
07-26/west-coast-district-coastal-processes-and-risk-modelling.pdf
The Green Book
Pro
tec
t c
oa
sta
l d
un
es
fro
m d
ev
elo
pm
en
t Description
This involves the conservation and restoration of dunes by supporting the reestablishment of
stabilizing vegetation. Plant species used for restoration should be native and adapted to the
harsh conditions present in dune environments. Soft physical structures such as wooden fences
or nets can be used to reduce wind speed across the sand surface and increase sand
deposition to facilitate the establishment of a stable vegetation cover. Involve the community
through local awareness raising campaigns to assist in protecting the dunes.
Goals
To prevent adjacent land, infrastructure and developments from inundation
Benefits
• Beach nourishment can complement hard protection measures such as seawalls and
provide additional protection. This will reduce maintenance cost of any hard protection
measures.
• Promote recreation and tourism through beach widening.
• Provide increased capacity for coping with coastal flooding.
• Natural dune systems are more aesthetically pleasing than hard defence measures and
structures.
Costs
Reduced maintenance costs of hard infrastructure. Low resource option. Involves initial
establishment (purchasing, planting and initial care) costs. Dunes require more space than
conventional, ‘hard’ engineering structures. This can be problematic when in highly populated
coastal areas, and conflicts of interest may arise, especially if coastal sand dune restoration
takes place in areas primarily used for residential or tourism purposes.
Example
Management and rehabilitation plan for the Hout Bay Dunes (Cape Town):
http://www.houtbayheritage.org.za/Hout-Bay-dune-management-report-Vol-2-final.pdf
The Green Book
Land use
manage
ment
Ma
inta
in &
re
ha
bilit
ate
du
ne
s DescriptionNatural sand dunes provide effective defence against coastal flooding, wave surges, and erosion. Theyare, however, in decline due to developments and are at increased risk from erosion caused by sealevel rise and more energetic wave climates and storm surges. Dune rehabilitation refers to the processof restoring /returning natural or artificial dunes that are degraded by active interventions to match, asclosely as possible, pre-disturbance conditions and functions. Dune rehabilitation methods include
building fences on the seaward side of an existing dune to trap sand and help to stabilise bare sandsurfaces, planting vegetation to stabilise natural and artificial dunes, and construction of artificial dunes.This action also includes measures of beach nourishment, which refers to the practice of adding largequantities of sand or sediment to beaches to combat erosion and increase beach width. It can also bereferred to as beach recharge, beach fill, replenishment, re-nourishment and beach feeding.Nourishment material should be compatible with the existing natural (or native) beach material.
GoalsRegular maintenance and rehabilitation of coastal dune systems will ensure the greatest coastalprotection benefits, including storm protection and decreased erosion, for both infrastructure andsettlements located along the coastal boundary.
Benefits• Beach nourishment can complement hard protection measures such as seawalls and provide
additional protection. This will reduce maintenance cost of any hard protection measures.• Promote recreation and tourism through beach widening.• Provide increased capacity for coping with coastal flooding.• Natural dune systems are more aesthetically pleasing than hard defence measures and structures.
CostsCompared to the construction of hard measures such as seawalls the costs of rehabilitation andmaintenance are substantially lower. Costs include that of depositing the dredged material onshoreand then the cost of reshaping with bulldozers. Additional costs could include dune grass or otherplants, costs of fencing and notice boards, and costs of transporting beach material. Costs would behigher where more complex operations are required, detailed designs needed, and when more
supervision or management is required during planning and implementation. Costs of continuedmonitoring and periodic re-nourishment to be done to maintain the effectiveness of the dune systemneed to be considered.
ExampleManagement and rehabilitation plan for the Hout Bay Dunes (Cape Town):
http://www.houtbayheritage.org.za/Hout-Bay-dune-management-report-Vol-2-final.pdf
The Green Book
Environ
mental
planning
conclusion
The Green Book
Climate change is expected to
amplify the extreme weather
events in South Africa,
particularly floods, droughts,
wildfires and storms. High
exposure and vulnerability of
settlements will transform even
small-scale and slow-onset
events into disasters. Recurrent,
small or medium-scale events
affecting the same communities
may have cumulative effects.
The Green Book project aims to
provide local government with a
decision support tool to
prioritise the integration of
climate change adaptation into
their budgeting and planning
instruments.
Given these risks, there is a
great need for investment in
adaptation actions in South
African settlements. Local
government is a critical role-
player that can build climate
resilience through “planning
human settlements and urban
development; the provision of
municipal infrastructure and
services; water and energy
demand management; and local
disaster response, amongst
others” (NCCRP, 2011).
Conclusion
